<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>

//1.外层的变量，内层可以找到（全局），内层的变量，外层找不到（局部）

/*function aaa(){
	var a = 10;
	//alert(a);
}

aaa();

alert(a);*/

var a = 10;
function aaa(){
	alert(a);
}

function bbb(){
	var a = 20;
	aaa();
}

bbb();

</script>
</head>

<body>
</body>
</html>
